Analytical Cytometry Core Shared Resource ABSTRACT To advance our understanding of cancer etiology and to develop improved therapeutic approaches, it is critical for researchers to have the ability to routinely analyze and isolate discrete cell types from complex heterogeneous populations. The Analytical Cytometry Core (ACC) fulfills this vital function for CC members by providing services to define and isolate discrete immune system cells and cancer cells based on cell surface markers, to quantify and isolate cells that express fluorescent markers, and to examine discrete cell growth states. The ACC provides flow cytometry analysis and sorting instrumentation (ten analyzers, four sorters) to support the research goals of the City of Hope Comprehensive Cancer Center (COHCCC). The ACC maintains several analysis instruments (BC Gallios, BC CyAn, BD C6, and two BD Fortessas) that enable varying degrees of parameter detection in the Furth building on the COH main campus. These instruments can be operated either by researchers or by core staff. A small particle analyzer (e.g., exosome and nanoparticle; NanoSight NS300) is also available at this location. Additional analyzers are available throughout the main campus and the City of Hope Biomedical Research Center (BC Gallios, two BD C6, BD Fortessa, and BD Fortessa X-20). Three high-parameter cell sorting instruments (BD Aria sorters), located on the main campus and the City of Hope Biomedical Research Center, are maintained and operated by core staff. An additional simple cell sorter (Bio- Rad S3), located on the main campus, is available for operation by individual researchers. Several additional instruments are on order with scheduled delivery in July 2017: a BD Fortessa X-20, a BD Aria Fusion sorter, and a state-of-the-art high-dimensional cytometer (BD FACSymphony). The core is directed by Dr. Jeremy Stark, a Professor in the Department of Cancer Genetics and Epigenetics, and supported by highly qualified staff that maintain and operate the equipment while also providing training to COHCCC researchers who wish to operate ACC instruments independently. Trained and authorized users have 24/7 access to the instrumentation, and core staff schedules are staggered to allow for an extended workday for core-assisted operation. Oversight is provided by an interdisciplinary faculty Advisory Committee, and user feedback through an annual survey. Over the past five years, the ACC was used by 142 unique investigators, including 94 CC members. Of the 94 CC members, 79 (84%) had peer-reviewed funding. Usage included members from all five Programs. Thus, the ACC provides accessible, cost-effective, and high quality flow cytometry services to support the research of the COHCCC.